It is 20,103 bases in length and encodes a protein of 236 amino acids (predicted molecular weight 25.809 kDa).

The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility.

[8] This protein plays a critical role in Hepatitis C attachment and/or cell entry by interacting with virus' E1/E2 glycoproteins heterodimer.

[12] HIV gag proteins use tetraspanin enriched microdomains (containing minimally CD81, CD82, CD63) as a platform for virion assembly and release.

[13] Engagement of CD81 lowers the signaling threshold required to trigger T-Cell\CD3 mediated proviral DNA in CD4+ T cells.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.